The Behavioral Assessment and Medical (BAM) Core is a new component of the competing TMARC renewal, that merges the Clinical Assessment and Laboratory (CAL) and Neuropsychiatric (NP) Cores from the prior funding period to improve resource efficiency. Now comprised of the Neuromedical and Laboratory Unit (NLU) and the Neuropsychiatric Unit (NPU), the BAM Core will extensively contribute to Center objectives by providing to TMARC Projects and Scientific Cores: 1) comprehensive neuromedical and neurobehavioral characterization of human participants, 2) specimen collection/management, and 3) collaboration and training regarding the analyses/interpretation of neuromedical, laboratory, and neurobehavioral data. Standardized neuromedical assessments will focus on aspects of health affected by HIV, METH and aging, including participants' medical and treatment history, neurological functioning, HIV disease staging, and medical comorbidity status (e.g., VACS Index, frailty). Laboratory assessments will include tests for co-infections, clinical lab assays (e.g., hepatic transaminases, hemoglobin), and soluble and cellular biomarkers in cerebrospinal fluid and blood that reflect HIV replication, immune functioning, and oxidative stress. New measures of biologic aging - cell senescence (telomere shortening) and mitochondrial aging (mtDNA injury) are added in support of TMARC's aging theme. The NLU also will provide assays for TMARC's animal projects and support for TMARC's pilot project on cell senescence. The NPU will provide comprehensive neurobehavioral assessments, including neurocognitive abilities, complex frontal systems behaviors (impulsivity/disinhibition, sensation-seeking, and apathy), comorbid psychiatric conditions (mood, ADHD, ASPD, and substance-related), plus key outcomes such as ART adherence, risky behaviors (unsafe sex, drug use, driving), performance-based lADL assessments, independence in real world functioning (e.g., lADLs, employment, health role functioning), psychosocial functioning (social and emotional functioning, quality of life) and support for TMARC's pilot project examining the utility of novel, virtual reality tasks to assess the everyday impact of neurobehavioral impairments due to METH, HIV and aging.